The present invention relates to display arrays. More specifically, the invention relates to techniques for driving such arrays.
Lewis, EP-A 0 540 163, describes switched capacitor analog circuits realized using polysilicon TFT CMOS techology. The circuits can be integrated as analog driving circuitry for large area electronic (LAE) devices such as active matrix liquid crystal displays (AMLCDs). As shown and described in relation to FIGS. 3A-9, a switched capacitor amplifier can be constructed from polysilicon TFTs and TFCs; at col. 10 lines 3-11, Lewis indicates that an array of such amplifiers could be used to provide the parallel drive needed for data lines of an active matrix display. As shown and described in relation to FIGS. 10-15B, display driver architecture with digital-to-analog converters (DACs) can be constructed from polysilicon TFTs and TFCs; a multiplexer at the output of each DAC allow the DAC to serve several lines.
Stewart, R. G., Lee, S. N., Ipri, A. C., Jose, D. L., Furst, D. A., Lipp, S. A., and Roach, W. R., "A 9V Polysilicon LCD with Integrated Gray-Scale Drivers," SID 90 Digest, pp. 319-322, describe a self-scanned polysilicon display in which both data-line and select-line driver circuits were fabricated simultaneously with an active-matrix liquid crystal display. Scanner circuits are shown and described in relation to FIG. 2, gray scale data scanners in relation to FIG. 3. Timing and gray scale conversion are shown and described in relation to FIGS. 4a and 4b. This display is also described in Lee, S. N., Stewart, R. G., Ipri, A., Jose, D., and Lipp, S., "A 5.times.9 Inch Polysilicon Gray-Scale Color Head Down Display Chip," 1990 IEEE International Solid-State Circuits Conference, IEEE, 1990, pp. 220 and 221.
Morozumi, S., Oguchi, K., Misawa, T., Araki, R., and Ohshima, H., "4.25-in. and 1.51-in. B/W and Full-Color LC Video Displays Addressed by Poly-Si TFTs," SID 84 Digest, 1984, pp. 316-319, describe a 1.51 inch active matrix LCD with drivers integrated on the same substrate. Left and right Y-drivers each include 210 bit shift registers and upper and lower X-drivers each include 180 bit shift registers and sample and hold circuits (referred to as "sample holders"). The sample and hold circuits receive a video signal and provide the video signal to data lines under control of shift registers. The outputs of the upper and lower sample and hold circuits may be connected to each other through data lines and the left and right shift registers may be connected to each other through gate lines, providing redundancy.